$OpenBSD: patch-src_main_connections_c,v 1.18 2015/06/23 15:14:52 feinerer Exp $
--- src/main/connections.c.orig	Fri May 22 00:15:20 2015
+++ src/main/connections.c	Fri Jun 19 18:52:41 2015
@@ -5251,7 +5251,8 @@ static Rboolean gzcon_open(Rconnection con)
 
     if(con->canread) {
 	/* read header */
-	char c, ccc, method, flags, dummy[6];
+	signed char c;
+	char ccc, method, flags, dummy[6];
 	unsigned char head[2];
 	uInt len;
 
